Question

a die is such that the number 6 is twice as likely to occur as any other number. If such a die is thrown once,find the probability of getting an odd number

Answer 1

First we need to find out the probability of each of the six outcomes.

Let the probability of getting 1,3 or 5 be x. Then the probability of getting 2,4 or 6 is 3x. We know that the sum of all six probabilities is 1. Solving equation

x+3x+x+3x+x+3x=1 or 12x =1

we get x=1/12.

So, probability to get 1,3 or 5 is 1/2, probability to get 2,4 or 6 is 3/12.

Prime numbers on a die are 2,3 and 5. The probability to get 2 is 3/12, the probability to get 3 is 1/12, the probability to get 5 is 1/12.

The probability to get a prime number is then

3/12+1/12+1/12 = 5/12.